My SO is not a lover of curly hair. I think it is just his personality. He likes neat and I think to him curly has the appearance of messy. But, I do not cater to his like of straight hair either so he must have decided he liked the curly hair enough to stick it out.
We have been together for 10 years and out of those 10 years my hair has probably been blown out or straightened maybe 20 times. I do not think we have to love everything about our significant other but as long as the good parts outweigh the parts we do not like so much-we are good.